Author Topic: Avidemux fixed my file but only on my PC? (SOLVED)  (Read 293 times)

Megane67

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Avidemux fixed my file but only on my PC? (SOLVED)
« on: September 20, 2019, 10:02:45 AM »
Greetings,

I was editing an mp4 file that had a audio sync error, the audio playing approximately one second too soon before the picture caught up with it.  After using Avidemux to shift the audio forward by 870 ms and saving the file, setting the video and audio formats to "Copy" and using the output format "MP4 Muxer", I tested the video on my VLC Player and it worked, the audio was now in perfect sync with the picture.  I then transferred the mp4 video over to my portable HD and connected it by USB cable to my Blu-Ray to watch on my HDTV downstairs.  But when I sat down to watch it, the audio sync error was back as if nothing had been changed or fixed.  The edited mp4 still works fine on my PC via VLC player though so I assume I saved it properly.  Did I miss something?  Any help with this issue would be greatly appreciated.

- Megane
« Last Edit: September 21, 2019, 10:01:42 PM by Megane67 »

eumagga0x2a

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Re: Avidemux fixed my file but only on my PC?
« Reply #1 on: September 20, 2019, 10:38:43 AM »
Do you use the latest Avidemux version?

The video player in the Blu-Ray device seems to have a crappy MP4 parser.

Megane67

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Re: Avidemux fixed my file but only on my PC?
« Reply #2 on: September 20, 2019, 08:59:12 PM »
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Do you use the latest Avidemux version?

Yep, I used the 2.7.5 Final version for Windows 64bit.  Everything worked fine except for not working on the Blu-Ray Player.

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The video player in the Blu-Ray device seems to have a crappy MP4 parser.

I didn't want to convert it to another video format and risk losing video quality as a result but I guess I can give it a try and hope for the best unless anyone else has any ideas?  Either way, thanks for the reply.

eumagga0x2a

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Re: Avidemux fixed my file but only on my PC?
« Reply #3 on: September 20, 2019, 10:16:28 PM »
As long as a container is compatible with the particular video codec, there is no need to re-encode video and the original video quality is fully preserved. If the device supports MKV, you could give it a try.

Alternatively, sacrifying the first GOP of the video could strongly reduce the video delay. This might work around the suspected deficiency (poor support or lack thereof for edit lists) of the MP4 parser of the Blu-Ray player.

Megane67

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Re: Avidemux fixed my file but only on my PC? (SOLVED)
« Reply #4 on: September 21, 2019, 10:01:22 PM »
Quote
As long as a container is compatible with the particular video codec, there is no need to re-encode video and the original video quality is fully preserved. If the device supports MKV, you could give it a try.

Alternatively, sacrifying the first GOP of the video could strongly reduce the video delay. This might work around the suspected deficiency (poor support or lack thereof for edit lists) of the MP4 parser of the Blu-Ray player.

Okay, after converting the file with Avidemux, I used the free program 'Format Factory' to convert the MP4 to MKV as close to the original values of the video file as possible and... it worked!   :D   The video file now plays with the sync fix perfectly on my Blu-Ray through USB on my Portable HD.  Thanks again for your help and advice!

eumagga0x2a

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Re: Avidemux fixed my file but only on my PC? (SOLVED)
« Reply #5 on: September 22, 2019, 11:19:13 AM »
Okay, after converting the file with Avidemux, I used the free program 'Format Factory' to convert the MP4 to MKV as close to the original values of the video file as possible

Did you re-encode? I meant using the MKV muxer in Avidemux in copy mode without any additional tools and especially without a lossy re-encode of the video stream.